The Critical Geometry for Initiation of Crevice Corrosion

Abstract

The critical crevice dimensions for which initiation of crevice corrosion occurs spontaneously was determined ex- perimentally for A1 in 0.05M NaC1. An artificial crevice at room temperature and pressure was employed to permit controlled variation of the crevice length and crevice gap over the ranges 5-15 and 0.1-0.6 ram, respectively. The range of conditions which led to corrosion initiation was compared with theoretical predictions based on a mathematical model of the concentration and the potential distribution within the crevice. It was found that the critical condition for initia- tion of crevice corrosion could be predicted in this system.